This invention relates to an improved portable fire hydrant that can be transported by a fire department to a water main and connected to a water main to supply fire fighting water. This invention also relates to a method of coupling an improved portable fire hydrant to a water main and a method of fighting a fire with the improved portable fire hydrant.
Conventional fire hydrants are well known and are disposed above ground level on a water main that is located below ground level. Typically, they include a cast iron or rigid steel structure that is fastened to a water main. A plurality of connectors for connecting the fire hydrant to a fire hose are generally disposed on the fire hydrant. Furthermore, the fire hydrant may have a plurality of connectors for connecting the fire hydrant to a water main. In many instances, these connectors are bolts or other fasteners that rigidly affix the fire hydrant to the water main.
Conventional fire hydrants may also include a valve operator disposed on the fire hydrant. The valve operator is coupled through a valve stem to a water main valve disposed in the water main below ground level. This valve operator may be manipulated by using a wrench or a similar mechanism designed to operate with the valve operator.
While conventional fire hydrants have proven to be satisfactory for some purposes, they have some disadvantages. For instance, since they are constructed from cast iron and are disposed above ground, they present a safety hazard. By way of illustration, automobiles or other vehicles can strike the fire hydrant causing damage to either or both the vehicle and the fire hydrant. If the fire hydrant is damaged, water pressure in the water main may decrease. Potentially, a loss of water for fire fighting or other purposes may occur. Similarly, people can inadvertently come into contact with a fire hydrant and injure themselves.
Because conventional fire hydrants are generally disposed curb side on a side walk, they have several other disadvantages. For instance, the amount of parking space that is available, which is a concern in relatively large cities, is decreased by the presence of conventional fire hydrants. In colder regions, in addition to removing snow from the streets, snow must be removed from the area surrounding these curb side fire hydrants. In some areas, the snow may be significant enough to cover a fire hydrant. Flags or poles have to be attached to the fire hydrants in these regions so that they can be readily located. Furthermore, since conventional fire hydrants are accessible, they are often opened for recreational purposes, especially in higher temperature climates. If the fire hydrants are opened, the water pressure in the attached water main will decrease. This causes several problems. For example, either less water for fire fighting purposes and for normal business and household use may be available or the rate at which this water is supplied may be decreased. This problem is more pronounced in large cities in the hotter periods of the year.
Because of these disadvantages, it has been suggested in the past that a portable fire hydrant be used. Once such fire hydrant is disclosed in U.S. Pat. No. 3,752,179 (Atkins). A portable fire hydrant may be carried by a fire department and installed on a water main to provide fire fighting water. Since a portable fire hydrant is not rigidly installed, it can overcome some of the drawbacks of permanently installed conventional fire hydrants. For instance, since it is removable, it will not be contacted accidentally be either people or vehicles. Furthermore, since it is removable, it need not be disposed curb side. For example, it could be attached to a water main located in a variety of places, including the middle of a street. By changing the location of where the fire hydrant attaches to a water main, several advantages are achieved. The amount of parking space is increased. If the water main to which the fire hydrant is to be attached is in the street, snow need only be removed in the street and the need for snow removal around a curb side fire hydrant is eliminated. Moreover, the likelihood of tampering with the water main to supply water for recreational purposes may be reduced if the water main to which the fire hydrant is to be attached is disposed in the street.
This invention relates to an improved portable fire hydrant that can be transported by a fire department and installed relatively easily into a water main and thereby overcome some of the problems presented by conventional fire hydrants. This invention also relates to a method of coupling an improved portable fire hydrant to a water main and a method of using the improved portable fire hydrant.
The portable fire hydrant of this invention can be coupled to a water main to provide fire fighting water. This portable fire hydrant may have an extension through which water can flow when the fire hydrant is coupled to the water main. Disposed on the extension may be an attaching mechanism for attaching the extension to a water main.
The portable fire hydrant may further include a valve operator coupled to the extension and a rod disposed within the extension that is coupled to the valve operator. In addition, a coupling mechanism may be disposed on one end of the rod. This coupling mechanism can be mated to a valve stem disposed in the water main. The valve stem of the water main is connected to a valve disposed in the water main. This water main valve controls the flow of water through the water main. When mated to the valve stem of the water main, the coupling mechanism couples the water main valve to the valve operator of the portable fire hydrant. Thus, manipulation of the valve operator will change the position of the water main valve and thereby supply water to the portable fire hydrant.
Disposed on the portable fire hydrant may be a sealing mechanism that includes an o-ring that runs around a periphery of the extension. When the extension is inserted onto the water main, the o-ring is compressed against an inner surface of the water main to seal the fire hydrant to the water main.
The sealing mechanism of the portable fire hydrant may also include an annular skirt disposed around the extension. This annular skirt creates an annular space between the skirt and the extension. The water main may have a flange that slidably engages the annular space between the skirt and the extension and thereby mates the portable fire hydrant with the water main.
As mentioned above, the portable fire hydrant may further include an attaching mechanism. The attaching mechanism may include a plurality of spring loaded members disposed on the extension. These spring loaded members are spring loaded towards the interior of the extension. The water main may have a plurality of apertures that are capable of receiving the spring loaded members. In order to secure the fire hydrant to the water main, the spring loaded members are driven into the apertures. More particularly, the spring loaded members move in response to operation of the valve operator. As described above, when the fire hydrant is mated with the extension, the valve operator is coupled to the valve stem of the water main valve. As the valve stem rotates in response to operation of the valve operator, a larger diameter section of the valve stem contacts the spring loaded members and pushes them towards the outer portion of the extension and into the apertures of the water main and thereby affixes the portable fire hydrant to the water main.
In further detail, the valve stem of the water main may have a portion that has a gradually reducing diameter proximal to a portion that has a relatively larger diameter. The portion of the valve stem that has the gradually reducing diameter is mated with the spring loaded members when the portable fire hydrant is attached to the water main. In this position, the spring loaded members are spring loaded towards the interior of the portable fire hydrant. When the valve operator is manipulated and the valve stem rotates to open the water main valve, the larger diameter portion of the valve stem comes into contact with the spring loaded members. As this occurs, the larger diameter portion of the valve stem pushes the spring loaded members towards the exterior of the portable fire hydrant and into the apertures disposed within the water main valve and thereby attaches the portable fire hydrant to the water main.
The portable fire hydrant may also include an aligning mechanism for aligning the fire hydrant with the water main upon installation. This aligning mechanism ensures that the spring loaded members of the attaching mechanism are properly aligned with the apertures of the water main. In a preferred embodiment, the aligning mechanism includes a plurality of keys disposed on the periphery of the extension. These keys mate with grooves disposed on the water main when the fire hydrant is coupled to the water main.
According to another aspect of this invention, a water main may include a pipe that has a flanged end that can be mated to the portable fire hydrant. The water main may also have a water main valve disposed within the water main and a valve stem extending from the water main to the flanged end. Disposed on the end of the valve stem, that is opposite the end that has the valve, is a connector for coupling the valve stem to the valve operator disposed on the portable fire hydrant.